散货船尾气弥散现象数值模拟研究
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摘要
对某型散货船的尾气弥散现象进行瞬态数值模拟研究,尾气中的气体组分扩散过程和颗粒相弥散过程分别采用组分扩散模型和Lagrangian颗粒多相流模型描述。计算结果表明:最佳的烟囱高度应为1.0～1.1倍日韩经验公式推荐值,最低高度应以日韩经验公式为参考;在设计航速下,若顺风速度接近船速,则尾气中的固相小颗粒会有少许飘落到甲板上,随着风速的进一步增加,飘落到尾部甲板上的小颗粒将明显增多。此外,数值模拟结果表明,对船员生活区产生危害的尾气主要成分是固相的小颗粒,而不是气体组分。因此,为了给船员提供安全健康的生活环境,应当着重关注尾气中固相小颗粒的弥散。
A transient numerical investigation on the exhausted gas dispersion in the surroundings has been conducted for a bulk carrier. The gas diffusion and tiny particles dispersion are described respectively by the multi-component diffusion model and Lagrangian particle multi-phase model. The calculation results show that the optimal funnel height should be 1.0 to 1.1 times the recommended value of the Japanese and Korean empirical formulas, and the minimum height should refer to the recommended value. At the design speed, a few small particles would fall to the deck when the downwind speed approaches the design speed. As the downwind speed increases, the small particles falling on the stern deck will increase significantly. In addition, the numerical simulation results show that the small solid particles in the exhausted gas are the main threat to the health of the crew rather than the gas components. Therefore, in order to provide the crew with a safe and healthy living environment, attention should be paid to the dispersion of small solid particles in the exhaust gas.
A transient numerical investigation on the exhausted gas dispersion in the surroundings has been conducted for a bulk carrier. The gas diffusion and tiny particles dispersion are described respectively by the multi-component diffusion model and Lagrangian particle multi-phase model. The calculation results show that the optimal funnel height should be 1.0 to 1.1 times the recommended value of the Japanese and Korean empirical formulas, and the minimum height should refer to the recommended value. At the design speed, a few small particles would fall to the deck when the downwind speed approaches the design speed. As the downwind speed increases, the small particles falling on the stern deck will increase significantly. In addition, the numerical simulation results show that the small solid particles in the exhausted gas are the main threat to the health of the crew rather than the gas components. Therefore, in order to provide the crew with a safe and healthy living environment, attention should be paid to the dispersion of small solid particles in the exhaust gas.
引文
[1]KULKARNI P R,SINGH S N,SESHADRI V.The Smoke Nuisance Problem on Ships-A Review[J].International Journal of Maritime Engineering,2005,147(5):270-276.
[2]SESHADRI V,SINGH S N,KULKARNI P R.Study of Problem of Exhaust Smoke Ingress into GT Intakes of a Naval Ship[J].Journal of Ship Technology,2006,2(1):22-35.
[3]OWER E,THIRD A D.Superstructure Design in Relation to the Descent of Funnel Smoke[C]//Trans.Institute of Marine Engineers(London).1959.
[4]THIRD A D,OWER E.Funnel Design and Smoke Plume[C]//Trans.Institute of Marine Engineers(London).1962.
[5]ACKER H G.Stack Design to Minimize Smoke Nuisance[C]//Trans.SNAME.1952.
[6]KULKARNI P R,SINGH S N,SESHADRI V.Behavior of Ship Funnel Exhaust in the Wake of a Bluff Body[C]//International Conference on Marine HydrodynamicsMarine CFD.2005.
[7]KIM J H,PARK S M,CHA H,et al.Numerical Research on Establishing Optimum Design Criterion of Ship’s Funnel[C]//International Mechanical Engineering Congress and Exposition ASME.2008.
[8]NOLAN R W.Design of Stacks to Minimize Smoke Nuisance[C]//Trans.SNAME.1946.
[9]MENTER F R,EGOROV Y.The Scale-Adaptive Simulation Method for Unsteady Turbulent Flow Predictions.Part 1:Theory and Model Description[J].Flow,Turbulence and Combustion,2010,85(1):113-138.
[10]MENTER F R,KUNTZ M,LANGTRY R B.Ten Years of Experience with the SST Turbulence Model[J].Heat and Mass Transfer,2003,4:625-632.
[2]SESHADRI V,SINGH S N,KULKARNI P R.Study of Problem of Exhaust Smoke Ingress into GT Intakes of a Naval Ship[J].Journal of Ship Technology,2006,2(1):22-35.
[3]OWER E,THIRD A D.Superstructure Design in Relation to the Descent of Funnel Smoke[C]//Trans.Institute of Marine Engineers(London).1959.
[4]THIRD A D,OWER E.Funnel Design and Smoke Plume[C]//Trans.Institute of Marine Engineers(London).1962.
[5]ACKER H G.Stack Design to Minimize Smoke Nuisance[C]//Trans.SNAME.1952.
[6]KULKARNI P R,SINGH S N,SESHADRI V.Behavior of Ship Funnel Exhaust in the Wake of a Bluff Body[C]//International Conference on Marine HydrodynamicsMarine CFD.2005.
[7]KIM J H,PARK S M,CHA H,et al.Numerical Research on Establishing Optimum Design Criterion of Ship’s Funnel[C]//International Mechanical Engineering Congress and Exposition ASME.2008.
[8]NOLAN R W.Design of Stacks to Minimize Smoke Nuisance[C]//Trans.SNAME.1946.
[9]MENTER F R,EGOROV Y.The Scale-Adaptive Simulation Method for Unsteady Turbulent Flow Predictions.Part 1:Theory and Model Description[J].Flow,Turbulence and Combustion,2010,85(1):113-138.
[10]MENTER F R,KUNTZ M,LANGTRY R B.Ten Years of Experience with the SST Turbulence Model[J].Heat and Mass Transfer,2003,4:625-632.